As a most basic wireless access technology, channel coding plays a crucial role in ensuring reliable data transmission. In an existing wireless communications system, channel coding is usually performed by using a turbo code, a low-density parity-check (LDPC) code, and a polar code. The turbo code cannot support information transmission at an excessively low or excessively high bit rate. However, for medium-packet or short-packet transmission, it is difficult for the turbo code and the LDPC code to implement desired performance when lengths of the codes are limited, due to coding/decoding characteristics of the turbo code and the LDPC code. In terms of implementation, the turbo code and the LDPC code have relatively high calculation complexity in a coding/decoding implementation process. Theoretically, it is proved that the polar code is a good code that can achieve a Shannon capacity and has relatively simple coding/decoding complexity, and for this reason, the polar code becomes more widely applied.
However, with rapid evolution of the wireless communications system, a future communications system, such as a fifth generation (5G) communications system, has some new characteristics. For example, three most typical communications scenarios include an enhanced mobile broadband (eMBB) Internet, massive machine type communication (mMTC), and ultra-reliable and low latency communications (URLLC). These communications scenarios impose a higher requirement on coding/decoding performance of the polar code.
A reliability order of polarized channels plays an important role in the coding/decoding performance of the polar code. However, in a current phase, accuracy of the reliability order of the polarized channels is not desired. Consequently, further improvement of the coding/decoding performance of the polar code in an application process is affected.